INTRACRANIAL CAVERNOUS MALFORMATIONS - LESION BEHAVIOR AND MANAGEMENTSTRATEGIES

INTRACRANIAL CAVERNOUS MALFORMATIONS are vascular anomalies consisting of endothelium-lined caverns filled with blood at various stages of t hrombosis and organization and separated by a collagenous stroma devoi d of mature vessel wall elements. They occur in an estimated 0.45 to 0 .9% of the population, with male and female patients equally affected and all ages represented. They commonly manifest as seizures, gross in tracranial hemorrhage, and focal neurological deficits. Lesions are fr equently multiple in the same patient, and 10 to 30% are associated wi th familial clustering. Several reports have documented a dynamic clin ical-radiological lesion behavior with de novo lesion genesis, intrale sional and perilesional hemorrhage, and corresponding fluctuations in lesion size. Hemorrhagic risk and neurological disability seem to be r elated to multiple factors, including lesion location, age, gender, st ate of reproductive cycle, and previous hemorrhage. Lesions may behave aggressively with repetitive hemorrhages and cumulative disability or may remain quiescent for many years. Management strategies include ex pectant follow-up in patients with asymptomatic or inaccessible lesion s, excision of symptomatic and accessible lesions, and radiosurgery of progressively symptomatic lesions in inoperable locations. Relevant d isease-specific outcome parameters are proposed to guide clinical deci sions and future research. Prospective, stratified, hypothesis-driven studies using rigorous epidemiological methods must be undertaken to d elineate patient and lesion factors influencing clinical aggressivenes s. Biological studies are essential to uncover strategies to predict a nd modify lesion behavior.